The autonomous sub scouring the depths of the Indian Ocean for Malaysia Airlines flight MH370 was finishing up the last five percent of the target area on Sunday — having discovered nothing of interest after 14 dives — but that doesn’t mean the mystery will go unsolved forever, experts said.
“They have a lot more region that they have to be looking through,” said Van Gurley, retired U.S. Navy captain who specializes in oceanography and undersea research.
Even though the batteries on the Malaysia Airlines jet’s black box are almost definitely exhausted since the plane has been missing for more than 50 days, previous “ping events” provide leads that are still very much viable, Gurley said.
“The fact that the black boxes are no longer pinging isn’t the end of the world,” he added.
When the U.S. Navy's Bluefin-21 robo-sub completes its search of a 6-mile radius area, it will have covered about 120-square miles, but Gurley said the pings indicated the jet could be anywhere within a 450-square mile area.
"If no contacts of interest are made, Bluefin-21 will continue to examine the areas adjacent to the 10-kilometer (6-mile) radius," according to a statement from the Australian search coordination center on Friday.
While Gurley said officials need “to be absolutely sure that they’ve covered that area before they start shifting and looking at other things,” the Bluefin-21 spent more than two weeks dedicated to the 120 miles.
“The longer you look in an area, the more sure they are, and they spent a lot of time focused on a pretty small area,” Gurley said.
Australian Defense Minister David Johnston said the plans for the next phase of the search will be announced next week. Johnston also said more powerful towed side-scan commercial sonar equipment with deeper diving capabilities might be deployed.
“The problem is that the Bluefin is operating right on the edge of its depth limit,” Gurley said. The more sophisticated technology can plunge 6,000 meters, while the Bluefin-21 can only reach 4,500 meters below the surface.
The depth of this section of the ocean floor is largely unknown because the terrain has “never really been mapped in detail,” Gurley said. “We know more about the surface of the moon.”
But planes flying overhead looking for debris are not doing much good at this point, said Gurley, who is now senior manager at Metro, Inc., a company that specializes in search planning and played a critical role in locating Air France Flight 447.
Authorities need to “focus more on the undersea side,” and additional sonar equipment would speed up that process.
“We have technology that can find things at the ocean bottom, they just move painfully slow,” Gurley said.
Still, Gurley predicts the question of what happened to MH370 and the 239 people on board will be answered “within a month or two, if the plane’s where the pings were heard.”
If the 450 square miles are searched and subs continue to come to the surface without a trace of the plane, “you’re back to a many years problem,” Gurley said, but he doesn’t think the search efforts would come to a halt.
In the situation in which officials need to start over and reevaluate where the plane ended up, Gurley said, “there will be periods where it feels like it has stopped or it has slowed down,” but “this is a mystery that will be solved.”